The combined process of UASB reactor, A/O reaction tank, secondary sedimentation tank, coagulating sedimentation and disinfect was used to treat the wastewater from food additive production with a treatment capacity of 300 m3/d when the influent COD, BOD5, NH3-N and SS were 2 500 ~ 3 000 mg/L, 900 ~ 1 100 mg/L, 120 ~ 140 mg/L and 200 ~ 250 mg/L, respectively. The effluent quality of the treated wastewater meet the first discharge standard stipulated in ”the integrated wastewater discharge standard (GB 8978-1996)”, which COD≤100 mg/L, BOD5≤20 mg/L, NH3-N≤15 mg/L and SS≤70 mg/L. The process has the advantages of stable operation, convenient management, easy operation and no secondary pollution.